Use the oslo fixture module

The oslo fixture import has been imported
And the tests code have been updated to use this new module

Change-Id: I3454440770402c028f49a92c6728d7bbad0c9aa0
Harden version checking for boto

Simple string comparison is not effective for version checking.
Let's switch to using pkg_resources.parse_version and compare
the tuples. Per review feedback, enabling the code path for
2.13 as well. Originally we had handled this by excluding
2.13 from requirements. With this we should be able to removing
the exclusion for 2.13 from global requirements.

Change-Id: Ie047f7201d8e6a9a9641000d387c4312506f49b1
Closes-Bug: #1239220
Fix NovaObject versioning attribute usage

A typo made early in the object prototyping process has meant that
all objects thus far have been exposing a version of '1.0' because
the base object has been using an attribute of 'version'. The
object implementations have been exposing a 'VERSION' attribute
with their desired version advertisement.

Since we are still relatively early in the process of deploying
objects, the impact from this should be relatively minor, although
it is important to get this fixed ASAP before any incompatible
object changes are made.

Change-Id: If9154dc663111f304f72ef7f6f37c465e84ff504
Closes-bug: #1239709
Merge "Use the oslo fixture module"
Merge "Harden version checking for boto"
Merge "Fix NovaObject versioning attribute usage"